Technical Field
The present invention relates to a shovel provided with an accumulator.
Description of Related Art
In related art, there is a known swing hydraulic motor control system that uses a single accumulator.
In this swing hydraulic motor control system, in order to recover kinetic energy of inertia operation of a swing hydraulic motor as hydraulic energy when decelerating the swing hydraulic motor, a working oil exited from the swing hydraulic motor is stored in an accumulator. In addition, in this swing hydraulic motor control system, in order to reuse the recovered oil energy as kinetic energy when accelerating the swing hydraulic motor, the working oil stored in the accumulator is supplied to the swing hydraulic motor.
However, this swing hydraulic motor control system is configured to use a single accumulator, and for this reason, a large-capacity accumulator capable of storing the working oil flowing out of the swing hydraulic motor at a time of a swing deceleration needs to be provided. Consequently, a relatively large amount of the working oil is required to increase the pressure of the accumulator. As a result, in a case in which the swing acceleration is performed in a state where the pressure of the accumulator is low due to an insufficient amount of the working oil stored in the accumulator at the time of the swing deceleration, the working oil accumulated in the accumulator cannot be released with respect to the swing hydraulic motor.